Butler, the chairman of the international boxing association's medical commission, believed Tavui's injuries weren't serious, but he exercised caution by sending the fighter to a hospital for evaluation and a CT scan.

"There was a tremendous amount of concern for this young man," Butler said. "I believe he will recover fully, but I couldn't take the chance of sending him home. The decision is always to do what's safe for the boxer, and don't worry about anything else."

Tavui clearly lost his equilibrium when he was staggered by a big right hand to his head in the third round, stumbling the length of the ring before finally flopping to the canvas. Tavui stood up as the referee counted, but staggered another distance before falling again.

"When I first got in the ring, his eyes were closed, and I had to raise his eyelids open," Butler said. "I think he was unconscious at that point, but for a very short time."

Tavui awoke and seemed able to raise and move his head as Butler called for a stretcher. The fighter was removed from Workers' Gymnasium four minutes later.

Tavui won the Oceania title at light heavyweight in 2007 and again this year, beating fighters from New Zealand, Australia and Tahiti. He is the only boxer representing Samoa at the Olympics.

"I don't enjoy such injuries, because it can always happen to me," Sivolija-Jelica said. "I am not cruel. I am an emotional boxer. I'm not pleased."